Thursday, March 17, 2011

Evolutionary Psychology: The Science of Human Nature


Having been tickled by Google Alert that my name had been mentioned in the comments at Pharyngula (P. Z. Myer's blog), I took a quick look. Just a few comments for now:

1) I became an evolutionary psychologist when studying the behavioral ecology of Microtus pennsylvanicus got boring. Those cute little field voles got boring because their ethology is relatively simple. Human ethology is a lot more interesting, mostly because it is a lot more complex. Should we not try to study it because it is more complex? Or because it might not jibe with some people's political preconceptions?

2) I assign Gould & Lewontin's "spandrels" paper to my students in evolutionary biology, along with various criticisms of it. I also assign Eldredge & Gould's "punk eek" paper and Gould and Vrba's "exaptation" paper (along with close to three dozen others, not to mention the entire Origin of Species, 1st. ed.). I also give them chunks of George William's 1966 classic, Adaptation and Natural Selection, so that they will know exactly how "onerous" the concept of "adaptation" actually is.

3) Here's the definition of "adaptation" I use:
An evolutionary adaptation is any heritable phenotypic character whose frequency of appearance in a population is the result of increased reproductive success relative to alternative versions of that heritable phenotypic character.
4) Here are the criteria I believe are most useful when one is attempting to determine if one is dealing with an "adaptation":
Qualification 1: An evolutionary adaptation will be expressed by most of the members of a given population, in a pattern that approximates a normal distribution;

Qualification 2: An evolutionary adaptation can be correlated with underlying anatomical and physiological structures, which constitute the efficient (or proximate) cause of the evolution of the adaptation;

Qualification 3: An evolutionary adaptation can be correlated with a pre-existing evolutionary environment of adaptation (EEA), the circumstances of which can then be correlated with differential survival and reproduction; and

Qualification 4: An evolutionary adaptation can be correlated with the presence and expression of an underlying gene or gene complex, which directly or indirectly causes and influences the expression of the phenotypic trait that constitutes the adaptation.
To me, it seems reasonable that if one can apply those to a specific human behavior, one can make arguments about its evolutionary derivation. Would anyone disagree?

As for the ridiculous idea that evolutionary psychology only deals with sex, has anyone making such a claim actually read a textbook on the subject? Here are several:

Human Evolutionary Psychology

Evolutionary Psychology: The New Science of the Mind (4th Edition)

Evolution and Human Behavior, 2nd Edition: Darwinian Perspectives on Human Nature

Evolutionary Psychology: The Science of Human Nature

[Full Disclosure Notice: The fourth title is indeed by Yours Truly.]

If you haven't, then please do so, and then we can discuss these questions.

While we're on the subject, Part II of Evolutionary Psychology: The Science of Human Nature (on the ethology of between-group behavior in humans) is coming out in May. My next project is an introductory textbook in evolutionary biology, entitled Evolutionary Biology: The Darwinian Revolutions, again in two parts. Part I (due out in September) is The Modern Synthesis and Part II (due out next May) is The Evolving Synthesis.

After that (if I live that long) will be On Purpose: The Evolution of Design by Means of Natural Selection (won't there be some fireworks when that comes out?), in which I present one of the core arguments for The Metaphysical Foundations of the Biological Sciences, in the spirit of E. A. Burtt's The Metaphysical Foundations of Modern Physical Science. Should be fun!

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As always, comments, criticisms, and suggestions are warmly welcomed!

--Allen

6 comments:

Roy said...

"Qualification 2: An evolutionary adaptation can be correlated with underlying anatomical and physiological structures, which constitute the efficient (or proximate) cause of the evolution of the adaptation;"
It's the underlying change in behavioral strategy that selects (or selects for) the change in physiological structures - at least according to those who favor adaptive mutation as the main evolutionary process.

Allen MacNeill said...

It seems to me that the only way a mutation can become adaptive is if those individuals carrying it survive and reproduce more often than those that don't. Under such conditions, such a mutation is adaptive by definition. That is, it increases in frequency in the population within which it is expressed.

I agree that the behavior is the proximate manifestation of the underlying mutation upon which selection acts. Ultimately, what matters is increased frequency of certain phenotypes relative to alternative phenotypes. It doesn't really matter how the phenotypes are expressed, only that they are.

Roy said...

" It doesn't really matter how the phenotypes are expressed, only that they are."
I'd say it matters that evolutionary changes are purposive and not simply accidents that come to serve that purpose. These biological strategies are far too complex to have been introduced by happy accident. We creatures take advantage of accidents to react strategically, rather than the other way around.

Vincent said...

I've always been a fan of evolutionary psychology when I started reading about it in college 9 years ago... It's been so long since I read anything about it. Glad I stumbled upon this blog, it looks great.

human psychology said...

i love your article..i have learned a lot about human nature..all us has a different kind of characteristics and have a different kinds of behavior that even others cannot understand..

Maria Maltseva said...

Thank you for your helpful posts. I appreciate them.